After the initial installation ownCloud will write some content into the .htaccess file such as the 404 or 403 directives. This adds a magic marker into the .htaccess file and only the content above this marker will be compared in the integrity checker.
This change requires the usage of a path instead of the App ID when signing code. This has the advantage that developers can also sign code under a different location to make it easier. (e.g. remove `.git`, …)
Also it adds an example command usage as well as a link to the documentation
This adds a hidden config flag that allows somebody to disable the code integrity check. If `integrity.check.disabled` is set to `true` in the config file:
1. The integrity check functions will return always an empty result
2. The integrity check is not performed when installing apps
3. The integrity check is not performed when updating apps
4. The integrity check is not performed when updating the core
Furthermore this adds support for a list of channels that the code checker will run on. At the moment this is only stable because I didn't want to break any build scripts that we have. Once we have a proper CA setup and updated the build process to sign the releases we can add the RC, alpha, beta as well as daily releases. So everything except "git" basically.
This PR implements the base foundation of the code signing and integrity check. In this PR implemented is the signing and verification logic, as well as commands to sign single apps or the core repository.
Furthermore, there is a basic implementation to display problems with the code integrity on the update screen.
Code signing basically happens the following way:
- There is a ownCloud Root Certificate authority stored `resources/codesigning/root.crt` (in this PR I also ship the private key which we obviously need to change before a release 😉). This certificate is not intended to be used for signing directly and only is used to sign new certificates.
- Using the `integrity:sign-core` and `integrity:sign-app` commands developers can sign either the core release or a single app. The core release needs to be signed with a certificate that has a CN of `core`, apps need to be signed with a certificate that either has a CN of `core` (shipped apps!) or the AppID.
- The command generates a signature.json file of the following format:
```json
{
"hashes": {
"/filename.php": "2401fed2eea6f2c1027c482a633e8e25cd46701f811e2d2c10dc213fd95fa60e350bccbbebdccc73a042b1a2799f673fbabadc783284cc288e4f1a1eacb74e3d",
"/lib/base.php": "55548cc16b457cd74241990cc9d3b72b6335f2e5f45eee95171da024087d114fcbc2effc3d5818a6d5d55f2ae960ab39fd0414d0c542b72a3b9e08eb21206dd9"
},
"certificate": "-----BEGIN CERTIFICATE-----MIIBvTCCASagAwIBAgIUPvawyqJwCwYazcv7iz16TWxfeUMwDQYJKoZIhvcNAQEF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\niG+UxI/MNcWV0uJg9S63LF8=\n-----END CERTIFICATE-----",
"signature": "U29tZVNpZ25lZERhdGFFeGFtcGxl"
}
```
`hashes` is an array of all files in the folder with their corresponding SHA512 hashes (this is actually quite cheap to calculate), the `certificate` is the certificate used for signing. It has to be issued by the ownCloud Root Authority and it's CN needs to be permitted to perform the required action. The `signature` is then a signature of the `hashes` which can be verified using the `certificate`.
Steps to do in other PRs, this is already a quite huge one:
- Add nag screen in case the code check fails to ensure that administrators are aware of this.
- Add code verification also to OCC upgrade and unify display code more.
- Add enforced code verification to apps shipped from the appstore with a level of "official"
- Add enfocrced code verification to apps shipped from the appstore that were already signed in a previous release
- Add some developer documentation on how devs can request their own certificate
- Check when installing ownCloud
- Add support for CRLs to allow revoking certificates
**Note:** The upgrade checks are only run when the instance has a defined release channel of `stable` (defined in `version.php`). If you want to test this, you need to change the channel thus and then generate the core signature:
```
➜ master git:(add-integrity-checker) ✗ ./occ integrity:sign-core --privateKey=resources/codesigning/core.key --certificate=resources/codesigning/core.crt
Successfully signed "core"
```
Then increase the version and you should see something like the following:
As you can see a failed code check will not prevent the further update. It will instead just be a notice to the admin. In a next step we will add some nag screen.
For packaging stable releases this requires the following additional steps as a last action before zipping:
1. Run `./occ integrity:sign-core` once
2. Run `./occ integrity:sign-app` _for each_ app. However, this can be simply automated using a simple foreach on the apps folder.
Lukas Reschke
Thomas Müller
